Though Robert Redford may be the very platonic ideal of a movie star -- a matinee idol from films such as "Butch Cassidy and the Sundance Kid,""The Sting," "The Way We Were," "The Electric Horseman" and "Out of Africa" -- he has of late been involved with smaller-scale, socially conscious dramas. So many were surprised last week by the news that Redford would be appearing in the Marvel Studios comic-book action sequel "Captain America: The Winter Soldier" as a senior leader in the secret government agency of S.H.I.E.L.D.

"I'm doing this film because it's different. It's a new thing for me," Redford explained during a Q&A as part of the L.A. Times Indie Focus Screening Series this week (you can play the clip above). The Academy Award winner was appearing at his own Sundance Sunset Cinema in support of his latest effort as director, producer and star, "The Company You Keep." A thriller about former '60s radicals forced to confront their pasts in the present day, "Company" also stars Shia LaBeouf, Brit Marling, Susan Sarandon and Julie Christie.

Though the 76-year-old Redford has not previously appeared in a contemporary superhero/comic-book movie like "Captain America," he added: "I think these films are really powerful. I think they're great. This is the kind of film I would have loved to see as a kid."

Star Chris Evans will reprise his title role from "Captain America: The First Avenger" in the sequel, which will be directed by Joe and Anthony Russo from a screenplay by Christopher Markus and Stephen McFeely, who also wrote the first film.

"I like the idea of stepping into new territory," Redford added. "I'm excited by it. I also think it's a good bunch of people who really know what they're doing."

The role is part of a busy year for Redford. Besides the opening of "The Company You Keep" on April 5, Redford will also appear in J.C. Chandor's "All Is Lost" later this year. The follow-up to Chandor's Oscar-nominated "Margin Call," the film is a physically demanding tale of survival at sea in which Redford is reportedly the only character on screen.